This invention generally relates to a guiding sheath which is especially suitable for guiding electrophysiology catheters. More particularly, a guiding catheter structure is provided which has a three-dimensional distal end which is particularly suitable for use during invasive cardiology procedures. One version of the guiding catheter curves in a direction especially suitable for posterior right use, while another version curves in a direction especially suitable for posterior left use. The latter configuration is especially suitable for transseptal procedures. The three-dimensional distal end is particularly useful in guiding an ablation catheter to direct its working distal end to the precise, desired location within the particular heart cavity being treated.
Guiding catheters are well known for use in providing a facilitating pathway for a treatment or diagnostic catheter. Often, such guiding catheters have shaped distal end portions which are useful in helping to properly locate the treatment or diagnostic catheter which passes therethrough. Often, the distal end portion of such a guiding catheter includes a bend or curve which can be generally characterized as two-dimensional. These types of curved or bent distal end portions generally lie within a single, two-dimensional plane, which plane also includes the elongated catheter shaft. A typical guiding catheter will include internal braiding in order to enhance pushability of the catheter through blood vessels and the like. Exemplary in this regard is Stevens U.S. Pat. No. 3,485,234, incorporated by reference hereinto.
Cannulas or sheath introducers are also generally known. Such devices have a passage therethrough for receiving a catheter and for guiding it during its initial stages of introduction into the body during a catheterization procedure. Often, these include hemostasis valving which takes the form of a self-sealing gasket. These introducer cannulas or sheaths can also include ports and side-tubes for introducing fluids and/or withdrawing fluids during various catheterization activities. Exemplary in this regard is Stevens U.S. Pat. No. 4,000,739, incorporated by reference hereinto. Sheath introducers typically follow a guidewire which had been introduced through a hollow needle during known procedures such as those which generally follow or modify the so-called Seldinger technique. Often, a guiding catheter is inserted through such a sheath introducer and into the blood vessel. Fernandez EP 755,694 shows a guiding catheter introducer assembly which includes an introducer sheath having a hemostasis valve, which sheath is attached or molded to a braided guiding catheter tubular body. This publication is incorporated by reference hereinto. Its distal end is shown to be generally straight or formed with a two-dimensional curve. The length of this guiding catheter is typical for guiding catheters, on the order of 100 cm so as to reach most locations within heart blood vessels.
Catheters having what can be characterized as a three-dimensional catheter distal end portion are generally known. An example in this regard is Obrez U.S. Pat. No. 4,169,464, incorporated by reference hereinto, which shows an angiographic catheter designed for selective catheterization of aortic branches such as various abdominal vessels. The three-dimensional shape of this catheter is particularly designed for facilitating such catheterization procedures.
Catheterization of the human heart at times necessitates having a catheter gain access to the atrium chambers. Generally speaking, access to the right atrium is gained through one of the femoral veins, typically the right femoral vein. Once a working catheter is within the right atrium, some procedures, such as ablation, require a pinpoint location of the catheter tip within the atrium cavity. At times, a guiding catheter having any of the known variety of curved distal ends, especially two-dimensional curved distal ends, does not provide the variation in movement which can be required and which can vary depending upon the needs of the procedure, the peculiarities of the patient, and the skill level of the cardiologist or other physician carrying out the procedure.
Similar pinpoint positioning requirements are encountered when attempting a catheterization procedure, such as an ablation, in the left atrium chamber. In addition, access to the left atrium is problematic. It is not possible to access the left atrium through the pulmonary artery, and access from the left ventricle is difficult. A typical approach for left atrium catheterization is a transseptal approach. With this known approach, access is gained through the right atrium by penetrating the interatrial septum. The transseptal approach is generally discussed in Mullins, "Transseptal Left Heart Catheterization: Experience With a New Technique in 520 Pediatric and Adult Patients", Pediatric Cardiology, 4:239-246, 1983; Saul et al, "Catheter Ablation of Accessory Atrioventricular Pathways in Young Patients: Use of Long Vascular Sheaths, the Transseptal Approach and a Retrograde Left Posterior Parallel Approach", Journal of American College of Cardiology, Vol. 21, No. 3, March, 1993, pp. 571-83; and Turi U.S. Pat. No. 5,312,341. Each of these is incorporated by reference hereinto.
Once access to the left atrium is attained by way of the transseptal approach, the difficulty remains in properly locating the treatment catheter tip, such as for an ablation procedure. As for a right atrium ablation, it is necessary to pinpoint a location for the ablation catheter treatment tip or the like. The location needed to be pinpointed could be within a difficult-to-access location along the inside wall of the atrium cavity. The arrhythmia to be controlled by ablation or the like can be at a location within the atrial cavity which cannot be readily accessed by the use of a straight guiding catheter or a guiding catheter having a heretofore known curved or bent distal end portion, including two-dimensional distal end curves. When eliminating accessory atrioventricular pathways by cardiac ablation techniques or the like, the pathway to be accessed can present a difficult maneuvering problem when using heretofore known guiding catheters. There is accordingly a need for a catheter-like guiding device which can be used in effecting pinpoint positioning of treatment or diagnostic catheters and the like, particularly when carrying out catheter cardiac ablation of the right atrium or of the left atrium by a transseptal procedure.